1. Field of Invention
My invention relates generally to land vehicles and more particularly to a safety fastener for ball and socket hitches that is structurally integrated with the hitch tongue to prevent a hitch socket from moving upwardly from a ball carrying it.
2. Background and Description of Prior Art
When first powered towing vehicle pulls a second towed vehicle, especially such as a non-powered trailer, for effective operation a hitch interconnecting the vehicles must allow motion of each vehicle relative to the other in three mutually perpendicular planes while yet providing an interconnection of appropriate strength, security and safety. A common and popular hitch that accomplishes these ends is the “ball and socket” hitch, which normally provides a spherical ball carried by a depending bolt for fastening on a rigid hitch bar carried by the towing vehicle and a hitch carried by the towed vehicle that defines a hemispherical chamber to pivotally receive the spherical ball. The hitch provides a fastening arm that communicates with the surface of the associated ball that is not covered by the hemispherical chamber of the hitch to releasably fasten the hitch on the ball and prevent it from being accidentally dislodged.
This type of ball and socket hitch is well known, simple of use, readily available and widely used, especially with trailers of lower and medial gross weight. This ball and socket hitch notwithstanding its popularity is not completely reliable or safe in use however as often forces encountered in normal towing usage may disengage the socket from the ball by disabling the internal fastening structure by either permanent or temporary forced reconfiguration. This problem has been recognized and dealt with in the past, commonly by providing a secondary safety connection such as a chain interconnecting the towing and towed vehicles. This solution though operative is not completely satisfactory as the interconnection of the two vehicles by flexible chain does not provide the same positional constraints for the vehicles relative to each other that is provided by the ball and socket hitch when interconnected and makes continued pulling by only the chain interconnection quite erratic and dangerous.
This problem has been recognized and responsively various other auxiliary safety devices have become known to operatively maintain the hitch socket on the associated ball. These known safety devices have generally been designed for and are only effectively operable with hitches for lighter towed vehicles. In the modern day, however, the trend in both towing vehicles and towed vehicles has been toward heavier vehicles and a need has arisen to provide a safety fastener for use with heavier vehicles that still allows use of the traditional ball and socket type hitch. The instant safety fastener seeks to fulfill this need.
Prior safety fasteners for lighter ball and socket hitches have not provided nor been required to provide completely structurally secure fastening of the safety fastener on the vehicle hitch bar while yet allowing three dimensional motion of a hitch relative to the ball supporting it. One method for providing such structurally secure fastening of a safety fastener has been to provide a safety fastener with a body defining a channel that completely surrounds the hitch beam of a towing vehicle that is to carry it with the bolt of the hitch ball extending through the body and hitch beam carried in the body channel to rigidly secure the elements, such as disclosed in the instant inventor's pending Utility patent application Ser. No. 10/696,315, filed Oct. 29, 2003. The body of that safety fastener provides the advantage of removal and replacement, but at the expense of a more massive, complex and expensive structure. The instant safety hitch provides similar safety structure but with no body and laterally spaced vertical fastening post collars to receive vertical fastening posts to support the horizontal fastening beam integrally carried directly by the hitch beam of the towing vehicle. This structure provides a safety fastener of less mass and cost that offers as great or greater strength but at the expense of removability. Experience has demonstrated that removability is not an essential requirement for a safety hitch and in many instances it is overshadowed by lower cost and the ability to acquire a safety hitch as an integral part of original equipment rather than a retro-fittable accessory.
Safety hitches that provide some fastening element above the socket of a ball and socket hitch to maintain interconnection of the socket on the ball have generally supported the fastening element in a cantilevered fashion, probably largely to prevent interference with motion of the socket on the ball while yet allowing relatively free pivotal motion of the elements relative to each other in three mutually perpendicular planes. The instant safety device provides two spacedly adjacent vertical fastening posts carried in vertical fastening post collars integrally supported by the hitch tongue for adjustable vertical motion with a horizontal fastening beam extending between the upper end portions of the vertical posts to provide a beam type member to restrain upward motion of the socket member in a substantially non-cantilevered fashion and to provide substantial strength and rigidity in excess of that provided by cantilevered type fastening members.
Prior safety fasteners that have provided a fastening element above the socket of a ball and socket hitch have generally been supported on the a hitch beam or hitch tongue by of some type of releasable mechanical interconnection because they generally have been designed as a retro-fittable accessory and this type of fastening probably is easier for a user to install. This construction generally has not provided the strength and structural rigidity as is provided by fastening structures having integral support directly on the hitch tongue. The instant safety fastener provides a base element having only two vertically oriented collars that are structurally carried by the opposed sides of the hitch tongue spacedly forwardly of the ball supported thereby. These collars are integrally joined to the hitch tongue by welding to allow the safety fastener to be used as a part of the originally manufactured product and also alternatively as a retro-fittable accessory, while yet providing the strength and rigidity of an integrally formed article of manufacture in either instance.
Though most ball and socket hitches for automotive vehicles have developed somewhat of a standardized configuration, there are some configurational variances between the hitches of various manufacturers. To accommodate such differences and allow use of the instant safety fastener on a substantial number of present day ball and socket hitches, it is necessary to make provision for adjustable vertical positioning of the horizontal fastening beam of the safety fastener relative to its support post collars. The instant safety fastener accommodates this requirement by providing to support post collars that allow sliding motion of support posts within their channels for adjustable vertical positioning. A plurality of similarly vertically spaced holes are defined in at least one of the collars and the support post carried therein to allow a fastening pin to extend through a cooperating set of such opposed holes to releasably maintain adjustable vertical positioning of the at least one vertical support arm relative to the collar carrying it.
With this pin type adjustment structure the fastening pin may be of a headed type with a lock structure at the end distal from the head to allow locking of the fastening pin in a cooperating set of adjustment holes to prevent unintentional removal of the socket element of a hitch from the associated ball and thusly prevent removal of a towed vehicle from a towing vehicle. Various prior safety fasteners have provided some means for adjusting the vertical position of a fastening arm relative to the hitch being fastened, but in general such prior fasteners have not used a pin and spaced hole type adjusting system with a key type lock to prevent unauthorized removal of the ball and socket hitch elements from each other.
My invention resides not in any one of these features individually but rather in the synergistic combination of all of its structures which necessarily give rise to the functions flowing therefrom as hereinafter further specified.